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0ad19a3f | 1 | /* |
2 | * lxc: linux Container library | |
3 | * | |
4 | * (C) Copyright IBM Corp. 2007, 2008 | |
5 | * | |
6 | * Authors: | |
9afe19d6 | 7 | * Daniel Lezcano <daniel.lezcano at free.fr> |
0ad19a3f | 8 | * |
9 | * This library is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU Lesser General Public | |
11 | * License as published by the Free Software Foundation; either | |
12 | * version 2.1 of the License, or (at your option) any later version. | |
13 | * | |
14 | * This library is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * Lesser General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU Lesser General Public | |
20 | * License along with this library; if not, write to the Free Software | |
250b1eec | 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
0ad19a3f | 22 | */ |
f1a4a029 ÇO |
23 | #ifndef __LXC_UTILS_H |
24 | #define __LXC_UTILS_H | |
0ad19a3f | 25 | |
c6868a1f CB |
26 | /* Properly support loop devices on 32bit systems. */ |
27 | #define _FILE_OFFSET_BITS 64 | |
28 | ||
a1e5280d CB |
29 | #include "config.h" |
30 | ||
6a44839f | 31 | #include <errno.h> |
61a1d519 | 32 | #include <stdarg.h> |
d0386d66 | 33 | #include <stdio.h> |
502657d5 | 34 | #include <stdbool.h> |
c6868a1f CB |
35 | #include <unistd.h> |
36 | #include <linux/loop.h> | |
5038d11a | 37 | #include <linux/types.h> |
ec346ea1 | 38 | #include <sys/syscall.h> |
c797a220 | 39 | #include <sys/types.h> |
a035c53a | 40 | #include <sys/vfs.h> |
f2363e38 | 41 | |
f749d524 CB |
42 | #ifdef HAVE_LINUX_MEMFD_H |
43 | #include <linux/memfd.h> | |
44 | #endif | |
45 | ||
37ef15bb | 46 | #include "file_utils.h" |
4295c5de | 47 | #include "initutils.h" |
279c45ee | 48 | #include "macro.h" |
37ef15bb | 49 | #include "string_utils.h" |
b07511df | 50 | |
60bf62d4 | 51 | /* returns 1 on success, 0 if there were any failures */ |
41dc7155 | 52 | extern int lxc_rmdir_onedev(const char *path, const char *exclude); |
7c11d57a | 53 | extern int get_u16(unsigned short *val, const char *arg, int base); |
1b09f2c0 | 54 | extern int mkdir_p(const char *dir, mode_t mode); |
fd8c2777 | 55 | extern char *get_rundir(void); |
9e60f51d | 56 | |
6a44839f DE |
57 | /* Define getline() if missing from the C library */ |
58 | #ifndef HAVE_GETLINE | |
59 | #ifdef HAVE_FGETLN | |
60 | #include <../include/getline.h> | |
61 | #endif | |
62 | #endif | |
63 | ||
9e320621 CB |
64 | #if !defined(__NR_setns) && !defined(__NR_set_ns) |
65 | #if defined(__x86_64__) | |
66 | #define __NR_setns 308 | |
67 | #elif defined(__i386__) | |
68 | #define __NR_setns 346 | |
69 | #elif defined(__arm__) | |
70 | #define __NR_setns 375 | |
71 | #elif defined(__aarch64__) | |
72 | #define __NR_setns 375 | |
73 | #elif defined(__powerpc__) | |
74 | #define __NR_setns 350 | |
75 | #elif defined(__s390__) | |
76 | #define __NR_setns 339 | |
77 | #endif | |
78 | #endif | |
79 | ||
6a44839f DE |
80 | /* Define setns() if missing from the C library */ |
81 | #ifndef HAVE_SETNS | |
82 | static inline int setns(int fd, int nstype) | |
83 | { | |
84 | #ifdef __NR_setns | |
85 | return syscall(__NR_setns, fd, nstype); | |
a1258e6d | 86 | #elif defined(__NR_set_ns) |
92e23841 | 87 | return syscall(__NR_set_ns, fd, nstype); |
6a44839f DE |
88 | #else |
89 | errno = ENOSYS; | |
90 | return -1; | |
91 | #endif | |
92 | } | |
93 | #endif | |
94 | ||
ac181b5c MPS |
95 | /* Define sethostname() if missing from the C library */ |
96 | #ifndef HAVE_SETHOSTNAME | |
b14fc100 | 97 | static inline int sethostname(const char *name, size_t len) |
ac181b5c MPS |
98 | { |
99 | #ifdef __NR_sethostname | |
100 | return syscall(__NR_sethostname, name, len); | |
101 | #else | |
102 | errno = ENOSYS; | |
103 | return -1; | |
104 | #endif | |
105 | } | |
106 | #endif | |
107 | ||
6a44839f DE |
108 | /* Define unshare() if missing from the C library */ |
109 | #ifndef HAVE_UNSHARE | |
110 | static inline int unshare(int flags) | |
111 | { | |
112 | #ifdef __NR_unshare | |
113 | return syscall(__NR_unshare, flags); | |
114 | #else | |
115 | errno = ENOSYS; | |
116 | return -1; | |
117 | #endif | |
118 | } | |
119 | #else | |
1a0e70ac | 120 | extern int unshare(int); |
6a44839f DE |
121 | #endif |
122 | ||
b5159817 DE |
123 | /* Define signalfd() if missing from the C library */ |
124 | #ifdef HAVE_SYS_SIGNALFD_H | |
125 | # include <sys/signalfd.h> | |
126 | #else | |
127 | /* assume kernel headers are too old */ | |
128 | #include <stdint.h> | |
129 | struct signalfd_siginfo | |
130 | { | |
131 | uint32_t ssi_signo; | |
132 | int32_t ssi_errno; | |
133 | int32_t ssi_code; | |
134 | uint32_t ssi_pid; | |
135 | uint32_t ssi_uid; | |
136 | int32_t ssi_fd; | |
137 | uint32_t ssi_tid; | |
138 | uint32_t ssi_band; | |
139 | uint32_t ssi_overrun; | |
140 | uint32_t ssi_trapno; | |
141 | int32_t ssi_status; | |
142 | int32_t ssi_int; | |
143 | uint64_t ssi_ptr; | |
144 | uint64_t ssi_utime; | |
145 | uint64_t ssi_stime; | |
146 | uint64_t ssi_addr; | |
147 | uint8_t __pad[48]; | |
148 | }; | |
149 | ||
150 | # ifndef __NR_signalfd4 | |
151 | /* assume kernel headers are too old */ | |
152 | # if __i386__ | |
153 | # define __NR_signalfd4 327 | |
154 | # elif __x86_64__ | |
155 | # define __NR_signalfd4 289 | |
156 | # elif __powerpc__ | |
157 | # define __NR_signalfd4 313 | |
158 | # elif __s390x__ | |
159 | # define __NR_signalfd4 322 | |
180edd67 SG |
160 | # elif __arm__ |
161 | # define __NR_signalfd4 355 | |
f53b5916 JC |
162 | # elif __mips__ && _MIPS_SIM == _ABIO32 |
163 | # define __NR_signalfd4 4324 | |
164 | # elif __mips__ && _MIPS_SIM == _ABI64 | |
165 | # define __NR_signalfd4 5283 | |
166 | # elif __mips__ && _MIPS_SIM == _ABIN32 | |
167 | # define __NR_signalfd4 6287 | |
b5159817 DE |
168 | # endif |
169 | #endif | |
170 | ||
171 | # ifndef __NR_signalfd | |
172 | /* assume kernel headers are too old */ | |
173 | # if __i386__ | |
174 | # define __NR_signalfd 321 | |
175 | # elif __x86_64__ | |
176 | # define __NR_signalfd 282 | |
177 | # elif __powerpc__ | |
178 | # define __NR_signalfd 305 | |
179 | # elif __s390x__ | |
180 | # define __NR_signalfd 316 | |
180edd67 SG |
181 | # elif __arm__ |
182 | # define __NR_signalfd 349 | |
f53b5916 JC |
183 | # elif __mips__ && _MIPS_SIM == _ABIO32 |
184 | # define __NR_signalfd 4317 | |
185 | # elif __mips__ && _MIPS_SIM == _ABI64 | |
186 | # define __NR_signalfd 5276 | |
187 | # elif __mips__ && _MIPS_SIM == _ABIN32 | |
188 | # define __NR_signalfd 6280 | |
b5159817 DE |
189 | # endif |
190 | #endif | |
191 | ||
192 | static inline int signalfd(int fd, const sigset_t *mask, int flags) | |
193 | { | |
194 | int retval; | |
195 | ||
196 | retval = syscall (__NR_signalfd4, fd, mask, _NSIG / 8, flags); | |
197 | if (errno == ENOSYS && flags == 0) | |
198 | retval = syscall (__NR_signalfd, fd, mask, _NSIG / 8); | |
199 | return retval; | |
200 | } | |
201 | #endif | |
202 | ||
f749d524 CB |
203 | #ifndef HAVE_MEMFD_CREATE |
204 | static inline int memfd_create(const char *name, unsigned int flags) { | |
205 | #ifndef __NR_memfd_create | |
206 | #if defined __i386__ | |
207 | #define __NR_memfd_create 356 | |
208 | #elif defined __x86_64__ | |
209 | #define __NR_memfd_create 319 | |
210 | #elif defined __arm__ | |
211 | #define __NR_memfd_create 385 | |
212 | #elif defined __aarch64__ | |
213 | #define __NR_memfd_create 279 | |
214 | #elif defined __s390__ | |
215 | #define __NR_memfd_create 350 | |
216 | #elif defined __powerpc__ | |
217 | #define __NR_memfd_create 360 | |
218 | #elif defined __sparc__ | |
219 | #define __NR_memfd_create 348 | |
220 | #elif defined __blackfin__ | |
221 | #define __NR_memfd_create 390 | |
222 | #elif defined __ia64__ | |
223 | #define __NR_memfd_create 1340 | |
224 | #elif defined _MIPS_SIM | |
225 | #if _MIPS_SIM == _MIPS_SIM_ABI32 | |
226 | #define __NR_memfd_create 4354 | |
227 | #endif | |
228 | #if _MIPS_SIM == _MIPS_SIM_NABI32 | |
229 | #define __NR_memfd_create 6318 | |
230 | #endif | |
231 | #if _MIPS_SIM == _MIPS_SIM_ABI64 | |
232 | #define __NR_memfd_create 5314 | |
233 | #endif | |
234 | #endif | |
235 | #endif | |
236 | #ifdef __NR_memfd_create | |
237 | return syscall(__NR_memfd_create, name, flags); | |
238 | #else | |
239 | errno = ENOSYS; | |
240 | return -1; | |
241 | #endif | |
242 | } | |
243 | #else | |
244 | extern int memfd_create(const char *name, unsigned int flags); | |
245 | #endif | |
246 | ||
b499121f CB |
247 | static inline int lxc_set_cloexec(int fd) |
248 | { | |
249 | return fcntl(fd, F_SETFD, FD_CLOEXEC); | |
250 | } | |
251 | ||
ebec9176 AM |
252 | /* Struct to carry child pid from lxc_popen() to lxc_pclose(). |
253 | * Not an opaque struct to allow direct access to the underlying FILE * | |
254 | * (i.e., struct lxc_popen_FILE *file; fgets(buf, sizeof(buf), file->f)) | |
255 | * without additional wrappers. | |
256 | */ | |
257 | struct lxc_popen_FILE { | |
8bd8018e | 258 | int pipe; |
ebec9176 AM |
259 | FILE *f; |
260 | pid_t child_pid; | |
261 | }; | |
262 | ||
263 | /* popen(command, "re") replacement that restores default signal mask | |
264 | * via sigprocmask(2) (unblocks all signals) after fork(2) but prior to calling exec(3). | |
265 | * In short, popen(command, "re") does pipe() + fork() + exec() | |
266 | * while lxc_popen(command) does pipe() + fork() + sigprocmask() + exec(). | |
ebec9176 AM |
267 | * Returns pointer to struct lxc_popen_FILE, that should be freed with lxc_pclose(). |
268 | * On error returns NULL. | |
269 | */ | |
270 | extern struct lxc_popen_FILE *lxc_popen(const char *command); | |
271 | ||
272 | /* pclose() replacement to be used on struct lxc_popen_FILE *, | |
273 | * returned by lxc_popen(). | |
274 | * Waits for associated process to terminate, returns its exit status and | |
275 | * frees resources, pointed to by struct lxc_popen_FILE *. | |
ebec9176 AM |
276 | */ |
277 | extern int lxc_pclose(struct lxc_popen_FILE *fp); | |
278 | ||
9be53773 SH |
279 | /* |
280 | * wait on a child we forked | |
281 | */ | |
282 | extern int wait_for_pid(pid_t pid); | |
c797a220 | 283 | extern int lxc_wait_for_pid_status(pid_t pid); |
9be53773 | 284 | |
3ce74686 SH |
285 | #if HAVE_LIBGNUTLS |
286 | #define SHA_DIGEST_LENGTH 20 | |
287 | extern int sha1sum_file(char *fnam, unsigned char *md_value); | |
288 | #endif | |
92f023dc | 289 | |
1a0e70ac | 290 | /* initialize rand with urandom */ |
508c263e | 291 | extern int randseed(bool); |
052616eb | 292 | |
477aa378 SH |
293 | /* are we unprivileged with respect to our namespaces */ |
294 | inline static bool am_guest_unpriv(void) { | |
295 | return geteuid() != 0; | |
296 | } | |
297 | ||
298 | /* are we unprivileged with respect to init_user_ns */ | |
5384e99d | 299 | inline static bool am_host_unpriv(void) |
4692c01a TA |
300 | { |
301 | FILE *f; | |
302 | uid_t user, host, count; | |
303 | int ret; | |
304 | ||
305 | if (geteuid() != 0) | |
306 | return true; | |
307 | ||
308 | /* Now: are we in a user namespace? Because then we're also | |
309 | * unprivileged. | |
310 | */ | |
311 | f = fopen("/proc/self/uid_map", "r"); | |
312 | if (!f) { | |
313 | return false; | |
314 | } | |
315 | ||
316 | ret = fscanf(f, "%u %u %u", &user, &host, &count); | |
317 | fclose(f); | |
318 | if (ret != 3) { | |
319 | return false; | |
320 | } | |
321 | ||
322 | if (user != 0 || host != 0 || count != UINT32_MAX) | |
323 | return true; | |
324 | return false; | |
1354955b | 325 | } |
5d897655 SH |
326 | |
327 | /* | |
328 | * parse /proc/self/uid_map to find what @orig maps to | |
329 | */ | |
330 | extern uid_t get_ns_uid(uid_t orig); | |
c476bdce SH |
331 | |
332 | extern bool dir_exists(const char *path); | |
93c379f0 ÇO |
333 | |
334 | #define FNV1A_64_INIT ((uint64_t)0xcbf29ce484222325ULL) | |
1a0e70ac CB |
335 | extern uint64_t fnv_64a_buf(void *buf, size_t len, uint64_t hval); |
336 | ||
f6310f18 | 337 | extern bool is_shared_mountpoint(const char *path); |
1a0e70ac CB |
338 | extern int detect_shared_rootfs(void); |
339 | extern bool detect_ramfs_rootfs(void); | |
340 | extern char *on_path(const char *cmd, const char *rootfs); | |
1a0e70ac CB |
341 | extern bool cgns_supported(void); |
342 | extern char *choose_init(const char *rootfs); | |
1a0e70ac | 343 | extern bool switch_to_ns(pid_t pid, const char *ns); |
1a0e70ac | 344 | extern char *get_template_path(const char *t); |
1a0e70ac CB |
345 | extern int safe_mount(const char *src, const char *dest, const char *fstype, |
346 | unsigned long flags, const void *data, | |
347 | const char *rootfs); | |
348 | extern int lxc_mount_proc_if_needed(const char *rootfs); | |
349 | extern int open_devnull(void); | |
350 | extern int set_stdfds(int fd); | |
351 | extern int null_stdfds(void); | |
1a0e70ac | 352 | extern int lxc_preserve_ns(const int pid, const char *ns); |
330ae3d3 CB |
353 | |
354 | /* Check whether a signal is blocked by a process. */ | |
573ad77f | 355 | extern bool task_blocks_signal(pid_t pid, int signal); |
6bc2eafe | 356 | |
dbaf55a3 | 357 | /* Switch to a new uid and gid. */ |
1a0e70ac CB |
358 | extern int lxc_switch_uid_gid(uid_t uid, gid_t gid); |
359 | extern int lxc_setgroups(int size, gid_t list[]); | |
dbaf55a3 | 360 | |
c6868a1f | 361 | /* Find an unused loop device and associate it with source. */ |
1a0e70ac | 362 | extern int lxc_prepare_loop_dev(const char *source, char *loop_dev, int flags); |
c6868a1f | 363 | |
74251e49 CB |
364 | /* Clear all mounts on a given node. |
365 | * >= 0 successfully cleared. The number returned is the number of umounts | |
366 | * performed. | |
367 | * < 0 error umounting. Return -errno. | |
368 | */ | |
1a0e70ac | 369 | extern int lxc_unstack_mountpoint(const char *path, bool lazy); |
74251e49 | 370 | |
ea3a694f CB |
371 | /* |
372 | * run_command runs a command and collect it's std{err,out} output in buf. | |
373 | * | |
374 | * @param[out] buf The buffer where the commands std{err,out] output will be | |
375 | * read into. If no output was produced, buf will be memset | |
376 | * to 0. | |
377 | * @param[in] buf_size The size of buf. This function will reserve one byte for | |
378 | * \0-termination. | |
379 | * @param[in] child_fn The function to be run in the child process. This | |
380 | * function must exec. | |
381 | * @param[in] args Arguments to be passed to child_fn. | |
382 | */ | |
1a0e70ac CB |
383 | extern int run_command(char *buf, size_t buf_size, int (*child_fn)(void *), |
384 | void *args); | |
ea3a694f | 385 | |
04ad7ffe CB |
386 | /* Concatenate all passed-in strings into one path. Do not fail. If any piece |
387 | * is not prefixed with '/', add a '/'. | |
388 | */ | |
eb5c2e6a | 389 | __attribute__((sentinel)) extern char *must_concat(const char *first, ...); |
0c3deb94 CB |
390 | __attribute__((sentinel)) extern char *must_make_path(const char *first, ...); |
391 | __attribute__((sentinel)) extern char *must_append_path(char *first, ...); | |
04ad7ffe CB |
392 | |
393 | /* return copy of string @entry; do not fail. */ | |
1a0e70ac | 394 | extern char *must_copy_string(const char *entry); |
04ad7ffe CB |
395 | |
396 | /* Re-alllocate a pointer, do not fail */ | |
1a0e70ac | 397 | extern void *must_realloc(void *orig, size_t sz); |
04ad7ffe | 398 | |
d75c14e2 | 399 | extern bool lxc_nic_exists(char *nic); |
0059379f CB |
400 | |
401 | static inline uint64_t lxc_getpagesize(void) | |
402 | { | |
403 | int64_t pgsz; | |
404 | ||
405 | pgsz = sysconf(_SC_PAGESIZE); | |
406 | if (pgsz <= 0) | |
407 | pgsz = 1 << 12; | |
408 | ||
409 | return pgsz; | |
410 | } | |
a035c53a | 411 | |
6222c3f4 CB |
412 | /* If n is not a power of 2 this function will return the next power of 2 |
413 | * greater than that number. Note that this function always returns the *next* | |
414 | * power of 2 *greater* that number not the *nearest*. For example, passing 1025 | |
415 | * as argument this function will return 2048 although the closest power of 2 | |
416 | * would be 1024. | |
417 | * If the caller passes in 0 they will receive 0 in return since this is invalid | |
418 | * input and 0 is not a power of 2. | |
419 | */ | |
420 | extern uint64_t lxc_find_next_power2(uint64_t n); | |
421 | ||
5288a74f CB |
422 | static inline pid_t lxc_raw_gettid(void) |
423 | { | |
424 | #ifdef SYS_gettid | |
425 | return syscall(SYS_gettid); | |
426 | #else | |
427 | return lxc_raw_getpid(); | |
428 | #endif | |
429 | } | |
430 | ||
1fd0f41e CB |
431 | /* Set a signal the child process will receive after the parent has died. */ |
432 | extern int lxc_set_death_signal(int signal); | |
a9d4ebc1 | 433 | extern int fd_cloexec(int fd, bool cloexec); |
d7ab0375 | 434 | extern int recursive_destroy(char *dirname); |
1fd0f41e | 435 | |
5b72de5f | 436 | #endif /* __LXC_UTILS_H */ |